Not yet recruitingPHASE3INTERVENTIONAL

De-scalation or swItch of Treatment According to Circulating tuMOr DNA Variation After 2 Cycles of Doublet Chemotherapy Plus Targeted Agent in Metastatic Unresectable Colorectal Cancer

This study, called DIAMOND, is for people with advanced bowel cancer that has spread and can't be removed by surgery. It aims to see if adjusting treatment based on a special blood test called 'circulating tumour DNA' (ctDNA) is better than standard treatment. ctDNA measures tiny bits of cancer DNA in your blood. The study will compare two groups: one where treatment is adapted early based on ctDNA changes after two cycles of chemotherapy, and another group receiving standard treatment. Researchers want to know if tailoring treatment in this way helps people live longer and have a better quality of life. Participants will receive chemotherapy and targeted drugs as a first treatment, and the study will follow their progress closely.

At a glance

Status

Not yet recruiting

Phase

PHASE3

Sponsor

University Hospital, Rouen

Enrolment target

408

Start

01 Jun 2026

Estimated completion

01 Jun 2032

Metastatic Colon Cancer

What is this study about?

This study is looking into a new way to guide treatment for people with advanced bowel (colorectal) cancer that has spread to other parts of the body and can't be removed with surgery. This type of cancer is called 'metastatic unresectable colorectal cancer'. The usual treatment often involves a combination of chemotherapy and targeted drugs. After a few cycles of treatment, doctors usually decide whether to reduce treatment or continue based on general guidelines.

This study introduces a new approach based on a special blood test called 'circulating tumour DNA' (ctDNA). This test looks for tiny fragments of cancer DNA in your blood. These fragments can give doctors clues about how well the treatment is working. Researchers believe that if the amount of ctDNA in your blood goes down significantly after the first two cycles of treatment, it might be possible to reduce or change your treatment earlier, potentially improving your quality of life without making the treatment less effective.

The main goal of this study is to see if using this ctDNA blood test to guide early changes in treatment leads to people living longer, and importantly, with a better quality of life, compared to the current standard approach. This is an important step in trying to make cancer treatments more personalised and effective for each individual.

Key takeaways

This study explores a personalised treatment approach for advanced bowel cancer.
It uses a blood test (ctDNA) to guide early treatment changes.
The goal is to improve how long people live while maintaining good quality of life.
Compares ctDNA-guided treatment to standard care.
Participants will receive chemotherapy and targeted drugs.
The study aims to make cancer treatment more effective and gentler where possible.

Who may be eligible?

To join this study, people generally need to be at least 18 years old and have advanced bowel cancer that has spread (metastatic) and can't be removed by surgery. Your cancer should be on the left side of your colon or in your rectum, and you shouldn't have had chemotherapy for this advanced cancer before. Doctors will also check that your general health is good enough to receive chemotherapy, including checking your blood counts, kidney, and liver function.

You would not be able to join if your cancer is on the right side of your colon, or if you've already had chemotherapy for your advanced cancer. Other reasons for not being able to join include certain heart conditions, uncontrolled high blood pressure, severe kidney or liver problems, or if you have a known allergy to any of the study medications. The medical team will review all your health information carefully to make sure the study is a good fit for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am 18 years old or older.
I have advanced bowel cancer that has spread and can't be operated on.
My cancer is on the left side of my colon or in my rectum.
I haven't had chemotherapy for this advanced cancer before.
My general health and organ functions are good enough for chemotherapy.

Answer every question to see your result.

What does participation involve?

If you join this study, you'll be randomly assigned to one of two groups, like flipping a coin for fairness. Both groups will start with a combination of chemotherapy and a targeted drug. The difference lies in how your treatment is managed after the first two cycles.

In one group, a special blood test for cancer DNA (ctDNA) will be used to guide whether your treatment is paused, changed to a milder maintenance treatment, or switched to a different type of chemotherapy with or without the targeted drug. In the other group, your treatment decisions will follow the standard approach, where doctors make choices based on how you're responding to treatment and their usual guidelines. You will have regular appointments and tests, including blood tests and scans, to monitor your health and how your treatment is working. The total time you spend in the study will depend on how your treatment progresses, but it aims to follow your journey closely.

Potential risks and benefits

Participating in this study might offer the benefit of a more tailored and potentially gentler treatment approach based on your body's response, which could lead to an improved quality of life if your treatment can be safely reduced. However, as with any medical treatment, there are potential risks associated with chemotherapy and targeted drugs, including side effects like tiredness, nausea, hair loss, or more serious reactions. The study will closely monitor your health to manage any side effects. You are free to withdraw from the study at any time, for any reason, without affecting your current or future medical care.

Locations (1)

CHU de ROUEN
Verified postcode
Rouen, France

Common questions

What is 'circulating tumour DNA' (ctDNA)?

It's a special blood test that looks for tiny pieces of cancer DNA that have been released into your bloodstream by tumour cells.

Why is it important to measure ctDNA?

Measuring ctDNA can help doctors understand how your cancer is responding to treatment very early on, sometimes even before changes show up on scans.

What does 'unresectable' mean?

It means the cancer has spread in a way that makes it impossible to remove by surgery.

What happens if I'm in the ctDNA-guided group?

After your first two cycles of treatment, the results from your ctDNA blood test will help your doctor decide if your treatment can be reduced, changed, or continued as before.

Will I still get standard treatment if I join?

Yes, even if you are in the ctDNA-guided group, you will start with chemotherapy and a targeted drug, which is a standard first-line treatment for your condition.

How to find out more

Frédéric Di Fiore, Pr

frederic.di-fiore@chu-rouen.fr 232886456 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.